Concrete-form.



F. A. RANDALL.

CONCRETE FORM.

APPLICATION FILED OCT. 3. 1916. l 31,993,921, IIIIeIIIeII 13611111919.

o u u n L *o I u r L u Q f I/I/ /I l II|I|I|II II a II I II II I II I I II II 0 I I I I I I I I I I III I III III III JI III III III III II III III III III III III I|| III III III III :I: III |I| III III I FRANK A. RANDALL, 0F CHICAGO, ILLINOIS.

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Specification of Letters Patent.

Y Patented Feb. 11, 1919.

'Application filed October 3, 1916. Serial No. 123,492. i

T0 all whom t may concern:

Be it known that I, FRANK A. RANDALL, a citizen of the United States, residing at Chicago, in the county of Cook and lState of Illinois, have invented a certain new and useful Improvement in Concrete-Forms, of which the following is a full, clear, concise, and exact description.

My invention relatesto improvements in concrete forms. Y

The object of the invention is to provide a form which may be removed from the concrete after the latter' has hardened, much more quickly and conveniently than those used heretofore.

In the accompanying drawing, I have illustrated a construction which embodies the invention.

Figure 1 is a top plan view of a concrete floor partly broken away to show the form beneath.

. Fig. 2 is a section on the line 2 2 of Fig. 1.

Fig. 3 is a top plan view of a modified construction, and Fig. 4 is a longitudinal section taken through onev endof one of the horizontal boards of the form.

The form is built up in the case of the flooring illustrated, by means of temporarily supported planks 1,-1, which support the inclined boards 2 2 thereon. The top memf bers consist of horizontal boards 3 3. They are supported on transverse toggle members consisting of boards 4 5 secured at their ends by boards G Gand 7 7. The boards 5 rest on the margins of the planks 1 and the boards 3 rest on the boards 4. The side boards 2 2 rest against the ends of the toggle members. The boards 7 7 project downwardly beneath the toggle members and are held in the desired relation by suitable fastening means such as iron loops 8 and wedges 9. After the concrete 10 has been poured and hardened the form may be readily removed by rst driving out the wedges 9, taking off the loops 8, moving the toggle members to the position shown in Fig. 1 and removing them.

It will be noted that the meeting edges of the boards 4 5 are beveled at 11 thereby permitting relative angular movement of the toggle members. Furthermore the boards 6 are secured to the opposite sides of the boards 4-5 from those to which the boards 7 are secured. Therefore, the line of pressure produced by the concrete when it sets,

is directedabout midway between the double thickness produced by the boards Yat the outer ends ofthe toggle members. In other words, the .line of pressure is indicated approximately by 12. Said pressure, therefore, tends to break the toggle joint as soon as the latter is freed of the restraining loops 8 and wedges 9.

To facilitate removal of the horizontal boards 3, they ends of the latter are connected by battens 13, adjacent to which, sheet metal angle plates 14 are located. Said angle plates have openings 15 therein into which a bar maybe inserted to pry the boards 3 away from the concrete after the toggle members and side boards 2, 2 have been removed. The side boards are also preferably fastened together by battens 16. All of said boards are therefore readily removed. The planks 1, 1 are supported in some suitable manner during theconstruction of the'form and during the pouring operation.

The form illustrated in Fig. 3 is the same as shown in Fig. 1 except thatthe toggle members are hinged to the side boards by hinges 17. They are also hinged to each other by additional hinges 18. With `this arrangement, the side boards and the toggle members are removed together.

Great difficulty has been experienced heretofore in removing forms of this character from the concrete without damaging said forms. The tamping of the concrete and the swellin of the timbers, due to the absorption og moisture, causes the parts to bind, thereby rendering the removal of the forms a diflicult operation. With the present arrangement, this binding pressure is resisted by the toggle members and is so utilized as to make it easier to remove said members rather than to make it more diiicult. The forms are preserved intact and may be used repeatedly in subsequent buildlng operations.

For convenience in disclosing the invention, I have illustrated it as applied to a floor construction in which some members have been referred to as horizontal and others as vertical. It is to be understood however, that these terms have been used merely in a relative sense. The invention is applicable to concrete forms arranged vertically as well as horizontally or at any angle. Furthermore, I do not wish to limit myself to wooden forms, as it is obvious that the required forms made of metal, or any other suitable material may be employed. In'

general the invention is not to be limited to the details of construction or relative arrangement of parts described herein except where limitations appear in the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. A concrete vform comprising side mem-k bers and top members pivoted members arranged to hold said side members apart and to supportl said top members andmeans for holding said pivoted members in alinement but permitting them to be moved angularly and removed.

2. A concrete form comprising bottom members, pivoted members resting thereon, top members resting on said pivoted members and upright members against the ends of the pivoted members, said pivoted members being beveled attheir meeting edges whereby the pressure developed during the setting of the concrete tends to break Vthe pivoted jointV and means for preventing said toggle joints, affording means for viforl cibly removing said top members.

Copies of this ypatent iiiay be obtained for 5. A concrete form comprising horizontal boards spaced apart, inclined boards supported thereon back from the edge thereof, togglelmembers supported at intervals von the margins of said boards, horizontal boards supported on said toggle members even with the topsot said inclined boards, battens connecting the ends of said top boards, sheet metal angleshaving openings therein secured to the under side 'of said top boards to facilitate removal t'hereot'and alinement, the binding of said side members against said compression members acting to automatically 'release the latter 'upon'the removal of saidlocking means.

f 7. A form for plastic material comprisf ing side members, pivoted 'members adapted when in alinement to hold said .side members apart, and temporary locking means for positively maintaining said pivoted members in operative jposition, the lateral pressure created bythe pouring of' plastic material into said form acting to automati-V cally displace said pivoted members upon the removal of said Ylocking means. j Y ln witness whereof, I 'hereunto subscribe my name this 30th day of September, A. D. 1916. Y

FRANK A. RANDALL( five cents each, by addressing' sie comiiss'ioner 'of Patents,

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